Tensioning apparatus for vibrator screens



Oct. 10, 1967' 'F. HOYT TENSIONING APPARATUS FOR VIBRATOR SCREEN Filed Jan. 5, 1966 40 Lil! FIGI.

' FIRMA'N G. HOYT United States Patent 3,346,114 TENSIONING APPARATUS FOR VIBRATOR SCREENS Firman G. Hoyt, Lancaster, Pa., assignor to Hoyt Wire Cloth Company, Lancaster, Pa., a corporation of Pennsylvania Filed Jan. 5, 1966, Ser. No. 518,949 8 Claims. (Cl. 209-403) ABSTRACT OF THE DISCLOSURE The present invention relates to material handling or classifying screens, and more particularly to an improved blind coupler or tensioning means for fastening a screen in its proper position relative to a vibrator assembly.

Vibrators having spaced upstanding and longitudinally extending side panels normally include longitudinally extending skirt boards positioned inwardly of the panels and pivotably abutting the interior sides of the panels so as to grasp or grip the edge of a wire cloth or screen and maintain tension thereon transversely of the vibrator. In order to tension each skirt board and thus the screen relative to the adjacent side panel, it is necessary to provide tensioning means on each skirt board and side panel, which tensioning means are preferably operable exteriorly of the side panels.

The present invention particularly relates to improvements in the tensioning means and comprises a bolt including a shaft having one threaded end portion fittable through an aperture in a panel and projecting externally thereof, and an opposite end portion having a T-shaped head thereon. In addition, the present invention provides a connector which is fixedly mounted on the outward side of the skirt board intermediate the board and the side panel, the connector having spaced upstanding side walls defining a slot and adapted to receive therebetween the T-shaped head. In order to lock the head to the connector, an aperture extends transversely of the slot through the side walls thereof, the aperture having radial termini in the side walls radially spaced one from the other and on opposite sides of the aperture. In addition, the connector is provided with means connecting the aperture with the slot whereby upon insertion of the head into the slot and rotation thereof into the aperture the termini of the aperture act as a stop for the head. Inthis manner blind coupling of the skirt board to the side'panel may be accomplished. In addition, a threaded nut, having preferably a hemispherical nose, connects the threaded portion of the shaft which projects through the aperture in the side panel, and attaches the bolt to the side panel.

State of the prior art Typically large vibrators used for sorting and/or classifying various materials are placed in'an elevated position on supporting structure with a grating 01' the like catwalks circumscribing the vibrator for servicing. The screening structure in the vibrato-r is conventionally broken up into panels, for example a vibrator 16 feet long by feet wide may have 4 separate panels each 4 feet by 5 feet. Depending upon the length of use and the material which is being sorted or grated, the normal screen panel has an average life of about 6 weeks under continuous heavy duty conditions. Normally such vibrators are placed in series, i.e. one superimposed of the other from the elevated position down to, for example, floor level. This means that if a single panel in any of the vibrating apparatus requires replacement, the whole line must be shut down until that screen panel has been replaced. Thus the more quickly worn out or broken panels ice are replaced the shorter the down time of the vibrator line and the less severe the economic loss incurred thereby.

As set forth above, conventionally the screen or wire cloth panels are coupled to the side plates via skirt boards having tensioning devices which pass through the side plates and permit tightening of the skirt boards to tension the screen panels. The Brugmann Patent No. 2,813,629 discloses a device for attaching and tensioning the screen panels which has been widely accepted in the field. In the Brugmann device a bolt is passed through the skirt board and the side plate, and as the bolt has a slotted body portion which extends through the opening in the side plate, a wedge-shaped member is placed in the slot and then driven home. The Brugmann device does have serious disadvantages. First of all the head of the bolt protrudes inwardly of the skirt board which permits the material being screened to abraid the head requiring replacement of the bolt. In addition, as when replacing a screen panel, alignment of the skirt board with the apertures and the side plate are critical and rather diflicult to make, it is necessary that a man be positioned interiorly of the vibrator to make such initial positioning, and a man be placed exteriorly of the vibrator on the grate-like catwalk for the like for driving the wedges. To hold the wedge and drive it as Well as position the bolt is difficult without dropping several pieces (which of course always seem to pass through the grating below). Thus the Brugmann apparatus is clumsy and it is not at all uncommon for the man positioned externally of the vibrator to drop several wedges and/or washers, which are normally mounted between the wedge and the side plate, when replacing a screen ing panel.

The Lambert device, as disclosed in Patent No. 3,092,573, eliminates the internal protrusion of the bolt head into the material working area, but does not eliminate the more serious problem of a cumbersome and easily separable connector, which like the Brugmann device is difiicult to maneuver and drop.

In View of the above it is a principal object of the present invention to provide a tensioning means for coupling the skirt board to the side plates, which tensioning means permit removal of the skirt board for replacement of screen panels without the concomitant risk of droppage of its parts.

Another object of the present invention is to provide a blind-coupling type tensioning means which will permit easy location and locking of the panel to the skirt board externally of the vibrator and which requires only an initial alignment by the person positioned interiorly of the vibrator.

Still another object of the present invention is to provide a self-seating coupler which will permit proper seating of a portion of the tensioning means against the side plate to reduce undesirable moments between the skirt board, side plate, and tensioning means.

Still another object of the present invention is to provide apparatus for use in conjunction with the tensioning means, which apparatus permits easy adaptation of the novel tensioning means to presently existing vibrators regardless of aperture size in the side plates.

Still a further object of the present invention is to provide, as part of the tensioning means, a novel connector which may be permanently secured outwardly of the skirt board between the skirt board and the side panel so as to cooperate in providing a fast and easy connection of the board to the plate while simultaneously tensioning the screening panel.

Other objects and a fuller understanding of the invention may be had by referring to the following specification and claims taken in conjunction with the accompanying drawing in which:

Patented Oct. 10, 1967 u FIG. 1 is a fragmentary plan view of a vibrator embodying the apparatus of the present invention;

FIG. 2 is an enlarged fragmentary sectional view taken along line 22 of FIG. 1;

1 FIG. 3 is an enlarged fragmentary view of the left hand portion of the apparatus illustrated in FIG. 2;

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a fragmentary sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged sectional view taken along line 66 of FIG. 5; and

FIG. 7 is an expanded perspective view of a portion of the apparatus illustrated in FIGS. 2-6, showing in solid lines the position of entry of a portion of the apparatus into the connector, and in dotted lines the position of that portion when engaged and locked in the connector.

Referring now to the drawing, and especially FIGS. 1 and 2 thereof, a material screening machine or vibrator 10 including screen or wire cloth-like material 11 supported by framework 12 is illustrated therein. The framework includes at least a pair of laterally spaced side panels 13 extending longitudinally of the screen, which panels afford the basic frame for coupling the screens 11. As shown, an eccentric shaft or the like arrangement 14 is coupled to the frame work 12 for effecting oscillatory motion to the vibrator.

As is conventional, the screen is connected to the laterally spaced side panels 13 by skirt boards 15, which through novel tensioning means 16, couple the skirt boards to the side panels. Each of the skirt boards is typically providing with a pair of legs 15a, 15b, the upper leg 15a pivotally abutting the interior of the side panel, and the lower leg 15b connecting longitudinally extending upturned flanges 17 located at the terminal edge of the screen. Bucker-up bars 18 and inturned ledges 19 serve to support the screen in a conventional manner.

In accordance with the invention novel tensioning means 16 are provided so as to enable removal of the skirt boards 15 for screen replacement as desired, without the operator having to remove several loose pieces and thereby run the concomitant risk of dropping the samel To this end, and as best shown in FIGS. 3, 4, and 7, each of the tensioning means comprises a bolt 20 including a shaft 21 having a threaded end portion 22 fittable through an aperture 23 spaced longitudinally along the side panels 13. The other end of the shaft 21 provided with a T- shaped head 23, preferably having a transverse width at its widest part greater than the width of the aperture 23 in the side panel 13 through which it is fitted. For reasons which will become more evident hereinafter, the threaded end portion 22 is provided with a radially extending slot 24 parallel to the T-shaped head 23.

In order to facilitate coupling of the skirt board 15 to the side panel 23 via the tensioning means 16, connecting means for the receipt and locking of the T-shaped head 23 is provided. As illustrated in FIGS. 3 and 4, the connecting means 30 is fixedly attached, as by a weld 31, to the outboard side of the skirt board (thus intermediate the board and the side panel when in position) and includes a pair of spaced upstanding side walls 32 defining a slot 33 adapted to receive therein the T-shaped head 23 associated with the bolt 20. Preferably the side walls are outwardly tapered as at 34 to define a mouth which permits for more easy insertion of the head into the slot 33 to compensate for small amounts of lateral misalignment. As best illustrated in FIGS. 5 and 7, an aperture 35 extends transversely to the slot 33 through the side walls 32, the aperture having radial termini 36 in the side walls radially spaced one from the other and on opposite sides of the aperture. Extending outwardly from each of the radial termini 36, but in opposite directions, is means defining -a hole 37. The means 37 permits rotation in one direction of the T-shaped head 23 into the aperture 35, upon insertion thereof into the slot 23. The final or locked position of the head 23 is shown in dotted lines in FIG. 7. To permit accommodation for some misalignment of the shaft 21 of the bolt 20 in the plane of an axis perpendicular to the slot 33, and even in the plane normal thereto, the means 37 defining a hole preferably has an outwardly angulated wall portion 38 to provide a wider mouth at the radial extremities of the connecting means. In this manner rotation of the head into the aperture 35 is assured, with the radially opposed termini 36 thereof acting as a stop for continued rotation of the head.

In order to secure the threaded end portion 22 of the bolt 20 to the side panel, a coupler, in the present instance a nut 40 having a hemispherical nose 41 thereon, is provided. (See FIGS. 3 and 4.) The hemispherical nose insures seating against the peripheral edges of the aperture in the side panels. As illustrated, the nut 40 is extra long in the axial direction to cover as much of the exposed portions of the threads as possible so as to prevent corrosion or the like from ruining the threads.

In certain instances the existing apertures in the side plates of a vibrator may have too great a diameter which would permit the T-shaped head 23 of the bolt to fall through upon disconnecting the shaft 21 from the connecting means 30. In addition, if the diameter is overly large it will be diflicult if not impossible to properly seat the nose 41 of the nut 40 against the periphery of the aperture without causing undesirable moment effects. In order to compensate for an oversized aperture, and permit the use of the tensioning means 16 as heretofore described with vibrators having any aperture size, it is desirable to provide additional or auxiliary seating means, such as the washer 42 illustrated in FIGS. 3 and 4. By providing an aperture 43 in the washer, and hemispherically relieving the periphery of the aperture 43, the nose 41 of the nut 40 will be permitted to seat therein and readily accommodate variations in the angle that the shaft makes perpendicular to the side panel 13. Of course upon initial installation the washer 42 may be tack-welded to the exterior of the side panel or, if such is not desired, may be left loose, although permanently securing the washer to the side panel has been found preferable.

As heretofore set forth, the leg 15a of the skirt board 15 pivots at its terminal end which abuts the interior of the side panel 13, and due to variations in screen width, it is preferable to provide means on the connecting means 30 which will permit a slight downward angulation thereof to insure proper receipt thereby of the T-shaped head 23. To this end, and as best shown in FIG. 6 (exaggerated), the portion 39 of the connecting means which abuts and is connected to the interior of the skirt board is provided with a slightly angulated face, 3-10 degrees being found sufficient in most instances. In this manner, increased angles from a line perpendicular and in the vertical plane to the slot 33 may be tolerated. The same effect may of course be achieved by relieving the side opposite the wall 38 of the means defining a hole 37. However, angulating slightly the portion 39 of the connecting means 30 has been found to achieve the same result and at a somewhat lower cost in fabrication.

In operation, the nut 40 is backed-off the threaded end 22 of the bolt 20 and the T-shaped head 23 inserted into the slot 33 of the connecting means 30, and then twisted clockwise (in the present instance) until the head is locked in the aperture 35. Thereafter the nut is tightened. When it is desired to replace a screen panel, it is only necessary to loosen the nut 40 until a screw driver or the like, placed in the slot 24, may cause counterclockwise rotation of the bolt 20 and then removal of the head 23 from the slot 33. If the aperture 23 in the side panel is of a correct size to prevent passage therethrough of the head 23 then the bolt and nut may be allowed to hang loosely connected to the interior of the panel. If the aperture is oversized, then the auxiliary seating means, if welded to the side panel, may be used as an effective stop to allow the bolt and nut to hang thereon.

Thus the tensioning means of the present invention permits easy coupling of the side panels to the skirt board and replacement of the screens without the risk of dropping any of its related parts. In addition, by the apparatus of the present invention blind coupling of the side panel to the skirt board is provided which lessens the downtime of vibrators for infield use.

Although the invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be made without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. In a vibrator having spaced upstanding and longitudinally extending side panels, longitudinally extending skirt boards positioned inwardly of said panels, each of said skirt boards comprising a panel including at least a pair of legs, one of said legs pivotably abutting the in terior side of said panel, the other of said legs adapted to grasp the edge of a wire cloth screen, and means for tensioning said board relative to said side panel; said tensioning means comprising: a bolt including a shaft having one threaded end portion fittable through an aperture in said panel and projecting externally thereof, and a second end portion of said shaft having a T-shaped head thereon, said head having a transverse width at its widest part greater than the width of said aperture; and a connector adapted to be fixedly mounted on the outboard side of said shirt board intermediate said board and said side panel, said connector having a pair of spaced upstanding side walls defining a slot adapted to receive therebetween said T-shaped head, an aperture transverse to said slot through said side walls thereof, said aperture having radial termini in said side walls radially spaced one from the other and on opposite sides of said aperture, and means connecting said aperture with said slot whereby upon insertion of said head into said slot and rotation thereof into said aperture, said termini act as a stop for said head; a threaded nut having a hemispherical nose for seating against the aperture in said side panel and connecting said threaded portion of said shaft projecting through said aperture in said side panel.

2. In a vibrator in accordance with claim 1 wherein said nut is elongated axially of said shaft so as to provide a covering for said threads projecting exteriorly of said panel.

3. In a vibrator in accordance with claim 1 wherein said one threaded end includes a radial slot parallel to said T-shaped portion of said head for blind location of said head and for facilitating rotation thereof.

4. In a vibrator in accordance with claim 1 wherein said spaced upstanding side walls are outwardly tapered so as to accommodate lateral misalignment of said head.

5. In a vibrator in accordance with claim 1 wherein said means connecting said aperture with said slot comproses oppositely and outwardly directed holes, each of said holes having an outwardly angulated wall portion to provide a wider opening at the radial extremities thereof.

6. In a vibrator in accordance with claim 1 wherein the portion of said connector adapted to be fixedly mounted on the outboard side of said skirt board includes an angulated face to accommodate variations in the angle of entry of said bolt into said connecting means.

7. In a vibrator in accordance with claim 1 including auxiliary seating means intermediate said nut and said side panel.

8. In a vibrator in accordance with claim 7 wherein said auxiliary seating means comprises a washer having an aperture therein of sufficient diameter to permit passage therethrough of said bolt, said aperture having a hemispherically relieved periphery to accommodate said nut.

References Cited UNITED STATES PATENTS 1,883,186 10/1932 Weber 209-403 2,813,629 11/1957 Brugmann 209-403 3,092,573 6/1963 Lambert et al. 209-403 3,219,065 11/1965 Moeller 209403 X HARRY B. THORNTON, Primary Examiner. TIM R. MILES, Examiner. 

1. IN A VIBRATOR HAVING SPACED UPSTANDING AND LONGITUDINALLY EXTENDING SIDE PANELS, LONGITUDINALLY EXTENDING SKIRT BOARDS POSITINED INWARDLY OF SAID PANELS EACH OF SAID SKIRT BOARDS COMPRISING A PANEL INCLUDING AT LEAST A PAIR OF LEGS, ONE OF SAID LEGS PIVOTABLY ABUTTING THE INTERIOR SIDE OF SAID PANEL, THE OTHER OF SAID LEGS ADAPTED TO GRASP THE EDGE OF A WIRE CLOTH SCREEN, AND MEANS FOR TENSIONING SAID BOARD RELATIVE TO SAID SIDE PANEL; SAID TENSIONING MEANS COMPRISING: A BOLT INCLUDING A SHAFT HAVING ONE THREADED END PORTION FITTABLE THROUGH AN APERTURE IN SAID PANEL AND PROJECTING EXTERNALLY THEREOF, AND A SECOND END PORTION OF SAID SHAFT HAVING A T-SHAPED HEAD THEREON, SAID HEAD HAVING A TRANSVERSE WIDTH AT ITS WIDEST PART GREATER THAN THE WIDTH OF SAID APERTURE; AND A CONNECTOR ADAPTED TO BE FIXEDLY MOUNTED ON THE OUTBOARD SIDE OF SAID SHIRT BOARD INTERMEDIATE SAID BOARD AND SAID SIDE PANEL, SAID CONNECTOR HAVING A PAIR OF SPACED UPSTANDING SIDE WALLS DEFINING A SLOT ADAPTED TO RECEIVE THEREBETWEEN SAID T-SHAPED HEAD, AN APERTURE TRANSVERSE TO SAID SLOT THROUGH SAID SIDE WALLS THEREOF, SAID APERTURE HAVING RADIAL TERMINI IN SAID SIDE WALLS RADIALLY SPACED ONE FROM THE OTHER AND ON OPPOSITE SIDES OF SAID APERTURE, AND MEANS CONNECTING SAID APERTURE WITH SAID SLOT WHEREBY UPON INSERTION OF SAID HEAS INTO SAID SLOT AND ROTATION THEREOF INTO SAID APERTURE, SAIDN TERMINI ACT AS A STOP FOR SAID HEAD; A THREADE NUT HAVING A HEMI SPHERICAL NOSE FOR SEATING AGAINST THE APERTURE IN SAID SIDE PANEL AND CONNECTING SAID THREADED PORTION OF SAID SHAFT PROJECTING THROUGH SAID APERTURE IN SAID SIDE PANEL. 